Is pre-implantation genetic testing right for you?
Modern medicine has revolutionized the way we predict a healthy baby’s future. Today, with pre-implantation genetic testing (PGT), doctors can screen for chromosomal abnormalities and genetic diseases even before pregnancy begins.
The process of in vitro fertilization (IVF) involves PGT, which currently includes three types of tests to ensure any embryo transferred to the woman is free of chromosomal abnormalities and genetic diseases.
PGT-A testing
PGT-A testing screens embryos for abnormal chromosome numbers. Many diseases can result from incorrect chromosome numbers, including Down syndrome and Turner syndrome. Abnormal chromosomes result from an unequal division of either sperm or egg cells.
Doctors offer PGT-A testing to individuals with a family history of chromosome problems as well as women over 37 who have a history of miscarriage or failed IVF cycles. One of the most common reasons an embryo transfer in IVF does not result in pregnancy is because of abnormal chromosomes.
PGT-M testing
PGT-M testing screens for monogenic (individual) genetic disorders. This test can help prospective parents prevent a genetic disease from affecting the next generation. The test screens embryos for genetic disorders, including:
- Huntington’s disease
- Sickle cell anemia
- Muscular dystrophy
- Cystic fibrosis
- BRCA1 & BRCA2 mutations
- Fragile-X syndrome
- Tay-Sachs disease
PGT-SR testing
Clinicians perform this test when one or both parents have a known chromosomal structural rearrangement. When a parent has a reciprocal translocation, Robertsonian translocation or an inversion in their chromosomal pattern, there is a high risk of miscarriage or having a child with a chromosomal genetic disorder. Their increased risk results from chromosomal patterns that make it difficult for the DNA to properly divide in the sperm or the egg.
How does PGT testing work?
After the egg is harvested and fertilized through IVF, doctors wait until the embryo reaches the blastocyst stage, usually at five or six days, to perform a biopsy. Three to 10 cells are removed from outside of the embryo to test for genetic disorders and chromosome problems. The cells that ultimately make the baby are not disturbed. The embryo is then frozen to await results, usually taking seven to 10 days. Healthy embryos are thawed and transferred to the woman in the next cycle.
Is there a risk with PGT?
PGT carries a small risk, with around 5% of embryos at risk of being damaged during the procedure.
How accurate is PGT?
PGT testing is very accurate, but not 100%. PGT-A testing is 98% accurate, PGT-M testing is 95-99% accurate and PGT-SR testing is 98% accurate.
How do you get PGT testing?
If you’re considering pregnancy and want to learn more about PGT, contact the clinicians at SIU today.
